1. Field of the Invention
The present invention relates generally to a backlight assembly and particularly to a backlight assembly without a bottom chassis.
2. Description of the Related Art
In general, a liquid crystal display (LCD) device displays an image by using the optical and electrical characteristics of liquid crystal molecules. The liquid crystal molecules have anisotropic refractivity and anisotropic dielectric constant. LCD devices have various advantages such as thinness, low driving voltage, and low power consumption, especially in comparison with other display devices such as a cathode ray tube (CRT) device, or a plasma display panel (PDP) device. For these advantages, LCD devices are widely used in a notebook computer, a monitor, a television receiver set, a mobile phone, etc.
The LCD device includes a lower substrate, an upper substrate and a liquid crystal layer disposed between the lower and upper substrates. When electric field is applied to the liquid crystal layer, the arrangement of liquid crystal molecules of the liquid crystal layer is altered to change its optical transmissivity, thus displaying the desired image.
As is well known, the liquid crystal display panel itself does not emit light—it only controls the propagation of light through the layer. Thus, the LCD device frequently uses a backlight assembly that provides the liquid crystal display panel with light.
The backlight assembly includes a lamp unit, a light guide plate (LGP), at least one optical sheet, and a reflecting plate. The lamp unit includes a lamp that outputs light and a lamp cover that covers the lamp. The LGP guides the light from the lamp unit toward the liquid crystal display panel. The optical sheet is disposed above the LGP in order to enhance the luminance of light exiting from the LGP. The reflecting plate is disposed under the LGP.
The backlight assembly includes a bottom chassis and one or two mold frames. The bottom chassis receives the lamp unit, the LGP, the optical sheet and the reflecting plate. The mold frame is combined with the bottom chassis for securing the lamp unit, the LGP, the optical sheet and the reflecting plate.
As mentioned above, a conventional LCD device includes a bottom chassis and a mold frame. These components increase manufacturing cost and assembly time. Furthermore, the bottom chassis covers the edges of the LCD device, necessitating an additional wire arranging element for securing a lamp wire and compromising heat dissipation.